Paper machine drive mechanism



y 1960 L. HORNBOSTEL 2,946,231

PAPER MACHINE; DRIVE MECHANISM Filed Sept. 26, 1955 hrEz fibr' LLOYDHORNBOSTEL PAPER MACHINE DRIVE MECHANISM Lloyd Hornbostel, Beloit, Wis.,assignor to Beloit Iron Works, Beloit, Wis., a corporation of WisconsinFiled Sept. 26, 1955, Ser. No. 536,710

4 Claims. (Cl. 74-395) This invention relates to a paper machine drivemechanism, and more particularly, to an improved main drive mechanism ormechanism for a variable speed line shaft drive.-

In the usual paper machine it is important that the speed of allsections of the paper machine be capable of simultaneous variation toallow for any changes to be made in thickness, character, and quantityof paper being made in the machine. In general, the paper machinesections comprise the forming wire, the press section, the dryers (whichmay include more than one section), and the calender stack. All of thesesections are driven through driving connections made with the variablespeed line shaft. Each connection made with the line shaft drives agiven section independently of the other sections and this connectionwill comprise a suitable speed change mechanism, since the individualsections are driven at diflerent speeds, that is, the surface speeds ofthe rolls or wire carrying the web in each of the sections aredifferent. This is because the paper web itself gets longer, by pressingin the press section, and shorter, by drying in the dryers. Accordingly,the press rolls must be operated at a greater speed than the dryerrolls. A difficulty here is that the amount of stretching in the pressesand the amount of shrinkage in the dryers varies with each kind of paperand with different operating speeds. The differences may be very greatat high operating speeds, although not too great at lower speeds. Thespeed change mechanism which interconmeets the variable speed line shaftWith each individual section thus is required to accommodate rathersubstantial differences in the ratios of speed change for differentoperating conditions. In recent times, paper Inachines are beingoperated at higher speeds than before, although such maximum speeds maynot be used at all times. Accordingly, the individual speed changemechanisms have been greatly overburdened and larger more expensive andmore complicated speed change mechanisms must be employed.

The instant invention affords a solution to the foregoing problemconfronting the Workers in the art, permitting the use of relativelysimplified and inexpensive speed change mechanisms for each of thesections. This is made possible in the instant invention by the use of adifferential gearing assembly to connect two portions or members of theline shaft, so that one portion of the line shaft may operate at a speedsubstantially different from the speed of the other under certainconditions. By way of explanation, it will be appreciated that atrelatively slow paper machine speeds both line shaft members or portionscould be driven at the same speed and the individual speed changemechanisms connected to each of the paper machine sections would not beovertaXed. But when the speed of the paper machine is greatly increased,the ordinary simplified speed change mechanisms cannot handle therequired changes and for this reason it has been necessary to go toadditional exatent 2,946,231 Patented July 26, 1960 pense anddevelopment in an efiort to provide adequate speed change mechanisms tocover all operating speeds for the machine. In other words, at such highoperating speeds the difference in the speed in the press section andthe speed in the dryers becomes so great that ordinary speed changedevices both connected to a line shaft operating at a single speed canimpart the desired speeds to the press section of the dryers only withdifficulty, if at all. In accordance with the instant invention,however, a diiferential gearing assembly is incorporated in the lineshaft so that one portion of the line shaft may operate at a given lowerspeed which readily permits the speed change mechanism'to drive thedryer and another portion operates at a greater speed which readilypermits the speed change mechanism connected with the press section tofunction. This permits a very substantial increase in flexibility ofoperation in the paper machine merely by the incorporation of oneadditional unit, the differential gearing assembly, in the variablespeed line shaft, without the necessity of changing or replacing thevarious speed change mechanisms connecting the line shaft with theindividual paper machine sections.

It is, therefore, an important object of the instant invention toprovide an improved drive for paper machines.

It is a further object of the instant invention to provide an improvedvariable speed line shaft drive mechanism for paper machines whichcomprises a difierential gearing assembly interconnecting portions ofthe line shaft to accommodate greater variations in the overall papermachine speed.

Other and further objects, features and advantages of the presentinvention Will become apparent to those skilled in the art from thefollowing detailed disclosure thereof and the drawings attached heretoand made a part hereof.

On the drawings:

Figure 1 is essentially a diagrammatical top plan view of a papermachine drive mechanism embodying the instant invention; and

Figure 2 is an enlarged detail view of a differential gearing assemblywhich may be employed in the practice of the instant invention.

As shown on the drawings:

In Figure 1 there is shown diagrammatically a paper machine in planview, indicated generally by the reference numeral 10, comprising acouch roll 11, a first press 12, a second press 13, a third press 14,(upper) dryer rolls 15, 16, 17, 18, 19 and 20 (and lower rolls 15', 16',etc.), and a calender stack 21. A variable speed line shaft in the formof two portions or members 22a22b provides the main source of power foroperating the paper machine, and the line shaft na -22b is driven by aprime mover or main drive means in the form of a steam engine 23suitably connected by a belt and pulley arrangement 24 to the line shaftportion 22b. As will be appreciated, in the prior art paper machines theline shaft 22a22b is a unitary member not separated by differentialgearing mechanism 25 (which will be described in detail hereinafter).

A suitable speed change mechanism 11a, diagrammatically shown in theform of cone pulleys and a belt, cooperating with bevel gears is drivenby the line shaft member 22a and translates the line shaft speed to thespeed desired for the couch roll 11. In like manner, speed changemechanisms 12a, 13w and 14a drive the first, second and third presses12., 13 and 14, respectively. It will be appreciated that other speedchange mechanisms may be employed here, but each type of speed changemechanism has certain limitations on the 3 speed changes which it canactually eifect, or which it can effect efficiently. In other words, agiven speed change device can be designed to operate effectively so asto reduce the line shaft speed in rpm. to a speed of perhaps 30 to 50%of the line shaft speed; but when such speed change mechanism is calledupon to selectively effect changes ranging from perhaps to as much as80% of the iine shaft speed, the device will operate ineficiently, if atall, at such extremes. Heretofore, the line shaft speed was the samethroughout the full length of the line shaft and the only known methodof accommodating these changes involved making changes in the individualspeed change mechanisms.

In particular, the presses 12, 13 and 14- operate at a greater speedthan the dryer rolls 15, 16, 17, etc. With faster overall paper machinespeeds, this difference becomes even greater. As will be seen, a speedchange mechanism 15a is also provided to interconnect the other lineshaft portion 22b and the dryer rolls, via a secondary shaft 15b and theusual bevel gear arrangement here indicated, and a speed changemechanism 21a interconnects the line shaft portion 22b and the calenderstack. 21. It will thus be seen that the line shaft portion 2212connected to the speed change mechanisms 15a and 21a for driving thedryer and calender stack may operate at a slower speed than the lineshaft portion 22a which drives the presses 12, 13 and 14. Thisdifference in operating speeds of the line shaft portions 22-5 and 22ais accomplished by the use of a differential gearing assembly 25.

Referring to Figure 2, which shows the differential gearing assembly 25in detail, it will be noted thatfthe line shaft portion 22b which isdriven by the main drive 23 corotatably mounts a gear 26 which in turnmeshes vwith and drives a gear 27 corotatably mounted on a sleeve 28that is freely rotatable on a shaft 29. The sleeve 28 also hascorotatably mounted thereon a (beveled) pinion 30. An opposed (beveled)pinion 31 is corotatably carried on still another shaft 32 and arotatable frame 33 carried by the shaft 29 carries opposed (beveled)pinions 34 and 3-5, each of Which meshes with both of the opposedpinions 3t) and 31. The frame 33 forms the arms of a T which carry attheir extremities the opposed pinions' 3'4 and 35 rotatable about thestem 29 of the T. The pinion 31 drives the shaft 32 which carriescorotatably mounted thereon a gear 36 meshing with the gear 37corotatably carried by the other line shaft portion 22a. The shaft 29has torque imparted thereto through a coro-tatably mounted gear 38meshing with a gear 39 directly connected to a torque-imparting unit,which in this case is a motor or drive unit 40 diagrammaticallyillustrated as being formed of cone pulleys 40a (on shaft 22b) and 40b(driving gear 39) with an interconnecting adjustable belt 4ilc. Othertorque-imparting devices may be used for the shaft 29 of thedifferential gearing assembly.

As is apparent, the opposed pinions 30 and 31 and the frame 33 (carryingthe opposed pinions 34 and 35) cooperate to define a differentialgearing assembly 30,- 31 and 33. The differential gearing assembly 30,31. and 33 permits differences in operating speeds of the. line shaftsections 22a and 22b. If the frame 33 has? sufficient torque appliedthereto to hold it against rotation, and the gears are the same size ashere indicated, then the speed of the driven line shaft portion22a'would be the sameras the speed of the driving line shaft portion22b; but, if the frame 33. is rotated in. one direction. or the otherthere will be differences in speed between the two: lineshaft portions22a and 22b. As previously explained at low operating speeds there. maybe no need to employ differences in line shaft speeds, but inthe higheroperating speeds a distinct advantage is obtained by driving the lineshaft portion 22a at a greater speed than that of the. line shaftportion 22b and the incorporation of the instant mechanism.25, thuspermits much greater flexibility in the operation ofithe paper machine.

As. will be-noted in the instant arrangement, the main drive means 23-is in driving connection with the first member 2212, and one rotary gearelement, the pinion 30, is in driven connection with the first member22b, while the other rotary gear element in the form of the pinion 31 isin driving connection with the second member 22a. The remaining rotarygear element in the form of the frame 33 is the control rotary gearelement in this embodiment and the unit 40 applies torque to the controlelement 33 in order to have the desired driving torque applied to thesecond member 22a.

It should be noted that in many cases only a slight speed differential(relative to the speed of the rotation of the shaft portions 22]) and22a) is required to obtain the desired operating conditions, and thepower applied or absorbed by the control element 33 in the differentialgearing arrangement of this invention bears substantially the same ratioto the total power required to drive the speed controlled shaft portion22b as the speed differential bears to the speed of the speed controlledshaft 22b. Accordingly, the controlling element 33', or the means fordriving the same, in this case the unit 40 may be very small in size andreadily controlled. If a separate speed controlled prime mover for theshaft portion 22a were used, such would have to be large in size anddifficult to control and its control would have to be correlatedprecisely with that of the prime mover 23 in order to effectsimultaneous changes in speed throughout the entire machine.

It will be understood that modifications and variations may be effectedwithout departing from the spirit and scopeof the novel concepts of thepresent invention.

I claim as my invention:

1. In a machine of the character described, a first driven line shaft, afirst plurality of variable speed drive means connecting with said lineshaft, a second driven line shaft, a second plurality of variable speeddrive means connecting with said second line shaft, a first plurality ofdriven members each of which connects with one of the first plurality ofvariable speed drive means and is driven thereby, a second plurality ofdriven members each of which connectswith one of said second pluralityof variable speed drive means and is driven thereby, drive meansconnecting with one of the driven line shafts to drive said shaft at abase speed, a differential gear assembly con nected to the first andsecond line shafts and having three rotary elements, the first of saidelements being connected to the line shaft which is connected to thedrive means, the second of said elements being connected to the otherline shaft, and the third of said elements being a control elementconnected to the first and second elements, and means applying torque tothe control element to establish a speed difference in the other lineshaft with respect to the one line shaft.

2. In a machine of the character described, a first driven line shaft, afirst plurality of variable speed drive means connecting with said lineshaft, a second driven lineshaft', a second plurality of variable speeddrive means connecting with said second line shaft, 21 first pluralityof driven members each of which connects with one of the first pluralityof variable speed drive means and-is driven thereby, a second pluralityof driven members each of which connects with one of said secondplurality of variable speed drive means and is driven thereby, drivemeans connecting with one of the driven line shafts to' drive said shaftat a base speed, a differential gear assembly connected to the first andsecond line shafts and having three rotary elements, the first of saidelements being connected to the line shaft which is connected to thedrive means, the second of said elements being connected to the otherline shaft, and the third of said elements being a control elementconnected to the first and second elements, and means applying torque tothe control element to establish a speed difierence in the other lineshaft with respect to a speed which may be varied from the base speedapplied to the one line shaft, the second plurality of driven membersbeing driven by the second plurality of variable speed drive means at aspeed which is unaffected by the speed variation applied to the firstplurality of driven members.

3. In a machine of the character described, a first driven line shaft, afirst plurality of variable speed drive means connecting with said lineshaft, a second driven line shaft, a second plurality of variable speeddrive means connecting with said second line shaft, a first plurality ofdriven members each of which connects with one of the first plurality ofvariable speed drive means and is driven thereby, a second plurality ofdriven members each of which connects with one of said second pluralityof variable speed drive means and is driven thereby, drive meansconnecting with the second driven line shaft to drive said shaft at abase speed, a difierential gear assembly connected to the first andsecond line shafts and having three rotary elements, the first of saidelements being connected to the second line shaft, the second of saidelements being connected to the first line shaft, and the third of saidelements being a control element connected to the first and secondelements, and means applying torque to the control element to establisha speed difference in the first line shaft with respect to the secondline shaft, the first plurality of driven members being thereby driventhrough the first plurality of variable speed drive means and the firstline shaft at a speed which may be varied from the base speed applied tothe second line shaft, the second plurality of driven members beingdriven by the second plurality of variable speed drive means at a speedwhich is unaffected by the speed variation applied to the firstplurality of driven members.

4. In a machine of the character described, a pair of groups of drivenmembers, one of said groups being driven at a speed which is unaffectedby the speed variation applied to the other group of driven members, apair of groups of variable speed drive means, one of said groups beingconnected to said one group of driven members and the other group ofvariable speed drive means being connected to said other group of drivenmembers, a pair of driven line shafts, one of said shafts beingconnected to said one group of variable speed drive means and the otherof said shafts to the other group of variable speed drive means, drivemeans connected to said one line shaft to drive said shaft at a basespeed, a differential gear assembly having three rotary elements, thefirst of said elements being connected to said other line shaft, thesecond of said elements being connected to said one line shaft, and thethird element being a control element connected to said first and secondelements, and means applying torque to the control element to establisha speed difierence in said one line shaft with respect to said otherline shaft.

References Cited in the file of this patent UNITED STATES PATENTS795,386 Cutter July 25, 1905 1,471,603 Headson Oct. 23, 1923 1,543,368Carrier July 23, 1925 2,144,307 Hallden Jan. 17, 1939 2,180,202 HalldenNov. 14, 1939 2,332,838 Borgward Oct. 26, 1943 2,357,201 Hornbostel Aug.29, 1944 FOREIGN PATENTS 375,099 France June 29, 1907 726,918 FranceMar. 15, 1932 857.359 France Sept. 9, 1940

